NEWARK, N.J. — The driver of a tractor-trailer that plowed into a limousine van carrying comedian Tracy Morgan and several friends, killing one and severely injuring Morgan and two others, was speeding in the final moments before the crash, according to a preliminary report released Thursday.

Wal-Mart driver Kevin Roper was going 65 mph in a 45 mph zone just before the June 7 crash on the New Jersey Turnpike, according to the National Transportation Safety Board’s report. The crash killed 62-year-old James McNair of Peekskill, New York.

The NTSB used the truck’s electronic engine-control system to calculate how fast Roper was driving.

“A preliminary review of the data showed that the Peterbilt combination vehicle was traveling at 65 mph for the 60 seconds preceding the collision with the Mercedes-Benz limo van,” the report concluded.

Traffic was slowed by construction that blocked two of the highway’s three northbound lanes. According to the NTSB report, a sign warned of the lane closures about a mile south of where the accident occurred, and another sign a half-mile closer directed motorists to reduce their speed from 55 mph to 45 mph.

According to a Turnpike authority spokesman, the speed limit in that stretch of the highway has been lowered from 65 mph to 55 mph since a widening project began in 2009.

Wal-Mart Stores Inc. trucks are equipped with devices that limit the vehicles’ speed to 65 mph, a spokeswoman said, so Roper was going at the top speed possible.

Drivers are required to follow the posted speed limit under Wal-Mart policy, spokeswoman Brooke Buchanan said Thursday. “Of course we expect our drivers to comply with the laws, whether it’s a speed limit, or (something else),” she said.

She otherwise declined to comment on the report, citing the ongoing investigation.

Messages left Thursday at several phone numbers listed for Roper’s attorney were not immediately returned.

The truck struck Morgan’s limo from behind, sending it into other vehicles and eventually onto its side. Morgan is hospitalized in fair condition with a broken leg and other injuries.

Morgan’s assistant, Jeffrey Millea, of Shelton, Connecticut, has also been upgraded to fair condition, according to Morgan’s spokesman. Hospital officials said Monday that comedian Ardie Fuqua, of Jersey City, remains in critical condition.

Roper, 35, of Jonesboro, Georgia, has pleaded not guilty to death by auto and assault by auto charges. A criminal complaint accuses him of not sleeping for more than 24 hours before the crash, a violation of New Jersey law.

The NTSB report said investigators were still probing Roper’s activities in the days leading up to the crash to determine the amount of rest he received.

It concluded that Roper left a Wal-Mart facility in Smyrna, Delaware, at about 11:30 a.m. on June 6 and made stops in Delaware, New Jersey and Pennsylvania during the day. Just after midnight on June 7 he left Bristol, Pennsylvania, en route to Perth Amboy, New Jersey, when the crash happened about 30 minutes into his trip.

The timetable appears to show Roper wasn’t in violation of federal rules that permit truck drivers to work up to 14 hours a day, with a maximum of 11 hours behind the wheel. He had been on duty about 13½ hours at the time of the accident, according to the report.

Roper is suspended pending the outcome of the investigation. He had worked for Wal-Mart since February, but applicants must have 250,000 lifetime miles driving a tractor-trailer, and 50,000 miles within the past three years, to be hired, Buchanan said.